The ticker image isn't showing up in my Yahoo mail, all I get is the text in a link. How do I get it to show up?

For Yahoo mail, you don't use the HTML code snippet, you use the image itself. There are instructions for Yahoo Mail here.

The next thing to try is checking your mail settings. For instance; you may have your email set to block images or you may be composing emails as plain text.

Blocking Images:

• If you are blocking images you will see this message above your email:
  This message contains blocked images.
  With a button for Show Images and Options. If you click on Options it will take you to Mail / Options / General. In the Spam Protection section there is a select box for Show images in emails. I have mine set to Always, except in Spam folder.
  
  Or you can go to Mail / Options / General to get to the same dialogue.

Composing E-mails: You also need to be in Rich text mode when you compose your email. In my copy of Yahoo, when you compose an email there is a link to Switch to Rich text (if you are in plain text mode) to the right of the subject line. If you are in Rich text mode, when you click on the Format tab, the font format select box etc are visible.

You need to be in Rich text mode, for your ticker to display as an image.

When I was in plain text mode, I found that I had to switch to Rich text, and then click on the New mail button again to get the ticker signature images to show up.

Of course, these notes are only from my experience with my Yahoo account, your account may differ from mine. You might need to check with Yahoo support.